This is a Mini-Mendel ( http://www.thingiverse.com/thing:1745 ) where many parts have been shelled (hollowed out) to 1mm (some 1.5 or 2mm for better printability).
This shall allow to use even less material in printing and apply the material where it counts for the mechanical structure (2-3 shell layers but very sparse infill).
Where appropriate I added supported and teardrops to make the shelled parts printable.
The idea is to supply the enormous demand for Mendel-parts by producing batches of hollowed Mini-Mendels very fast and with very little materisl. Then to give these to the people to be filled with Epoxy, so they can print full Mendel-parts and sell the MiniMendel to the next person or to just stay with the MiniMendel as it is.

Total

• 35977 seconds = 9h 59min 37 seconds for a complete Mini-Mendel
• theory: 101.97 cubic centimeter of material = 110 gramm ob ABS (1/3 of the solid Mini-Mendel and 1/10 of a regular Mendel)
  (calculated using Skeinforge with 0.4mm layer-thickness at 32mm/s)
• actual print: 152g of ABS including rafts
• Build documentation: http://objects.reprap.org/wiki/Mini-Mendel

(Sadly the license must be GPL 2 as the Mini Mendel is GPL2 instead of a license appropriate to hardware-designs.)

changes of version 1.2:

• more parts shelled
• some bugfixes
• more supports to make the parts stronger and easier to print
• exported as STL
• exported as Solidworks
• exported to ACIS R19 (.sat)
• exported as STEP

changes of version 1.2.2:

• all STL-part oriented properly for printing
• all STL-files checked through Netfabb auto-repair (no issues found)

changes of version 1.3:

• x-carriage-lower-left_1off was missing holes on the ends of the teardrops.
• thicker shells on the roof of wide horizontal holes
• center STL of z-bar-top-clamp_2 on print-bed
• some parts are missing in the STL or had the incorrect number of copies.
  They are now correctly named "_Xoff" in the STL-files (not the solid model)

TODO:

• center STL of z-bar-top-clamp_2 on print-bed

The original files can be opened and exported in Alibre Design (trial version. Too many parts in assembly for the free version.). For other solid modelers exports as Step, SolidWorks and Acis are provided.

• print (chosen temperature should be adequate to allow 1-2cm of overhangs)
• fill the more fragile parts with epoxy-resin or similar (make sure it is thick enough to not leak between cracks)
• add electronics, extruder, stepper-motors, screws, bearings and print-plate
  See http://objects.reprap.org/wiki/Mini-Mendel for parts needed and sources.

Forum-Thread in the RepRap-Forum:
http://forums.reprap.org/read.php?151,43636
Forum-Thread in the BfB-Forum:
http://www.bitsfrombytes.com/fora/user/index.php?topic=697.0